In this seemingly dystopian society that has been forced on us for the last year and a half, several terms have become commonplace in our daily conversations.  MRNA vaccines, gain of function in viruses, and convalescent plasma, to name a few.  Another term, monoclonal antibodies, has gained favor in the treatment of COVID-19, and we have one, Regeneron, available here at CCMH!

     Regeneron is a combination of two monoclonal antibodies, casirivimab and imdevimab, which has been shown to reduce viral load in patients who test positive for COVID-19.  (Here’s a hint to make you look like you know your stuff in medical conversations, any drug with a generic name that ends in the suffix “mab” is a monoclonal antibody.  The letters “mab” stand for Monoclonal AntiBody!)  But what, exactly, IS a monoclonal antibody?

     Monoclonal antibodies are man-made proteins that act like human antibodies in the immune system.  As the name suggests, they are synthetically cloned from mouse or human proteins, and have been used in oncology for several years, as an adjunct or alternative to harsher chemotherapy regimens, and several medications for arthritis or inflammatory bowel disease are in fact, monoclonal antibodies. 

     Regeneron acts in a similar manner to other monoclonal antibodies, in that it produces targeted therapy to a specific cell or structure.  Once injected with Regeneron, the medication seeks out the spike protein that sticks out of the coronavirus that causes COVID-19.  Once attached to the spike protein, the virus’ ability to enter cells is blocked, and thus, the infection is slowed.  As a result, serious infection and hospitalization of patients is reduced dramatically, in some studies by 72% to 93%.    

     Here at CCMH, Regeneron is given as an outpatient IV infusion, if you test positive for COVID -19.  The infusion takes about an hour, and then you are sent home.  The sooner you receive Regeneron after experiencing symptoms of COVID-19 the better, but there is actually a ten-day window to receive the medication following onset of symptoms, where it is still effective.  Side effects are rare, but can include redness at the injection site, fever, chills, and nausea.  Perhaps the best thing about Regeneron is the cost, the drug is provided free of charge, much like the COVID-19 vaccines.  Eligibility was expanded in August to include individuals who think they may have been exposed to COVID-19 and are at high risk of getting severe symptoms of COVID-19.  As always, consult your physician or medical provider with any additional questions. 

                                                                                                                Herb Hunter, PharmD, BCPS